Our Story
In 2022, as experienced sonographers, Emily and Jo began closely examining the accuracy of third-trimester growth scans. We were surprised by the lack of a reliable, standardised method to assess the accuracy of estimated fetal weight (EFW) predictions, both locally and nationally. The primary benchmark for evaluating accuracy remained the detection rate of babies born below the 3rd centile. While this metric had its merits, it felt inadequate—it didn’t fully reflect the accuracy of the scans. For instance, if we consistently under-measured all babies, we could achieve high detection rates yet still be inaccurate, leading to unnecessary interventions such as induction of labour or caesarean. These interventions carry risks and place a significant financial burden on healthcare services.
Another available approach was retrospective image auditing, which is highly subjective and time-consuming. When we reached out to other hospitals, we found widespread inconsistencies in how growth scan accuracy was assessed across different trusts.
Frustrated by this, we set out to improve accuracy rates in our own Trust. However, we quickly realised we lacked an effective way to measure the impact of any changes we were making. This triggered a deeper exploration of the evidence used to guide growth scans, and we were surprised to find how small the patient cohorts often were and how weak the supporting evidence could be.
Given the vast amount of patient data routinely collected, it became clear that there had to be a better, more data-driven solution. This inspired Emily to work with a data scientist, creating the Antenatal Sonography Toolkit (AST), designed to help teams effectively assess their growth scan accuracy at both a departmental and individual clinician level. The AST can also be used as a tool to assess quality improvement initiatives and pinpoint root causes of inaccuracy. Our vision is to use the AST to develop a new, more effective, and clinically useful national benchmark for growth scan accuracy.